Azithromycin Dosing for Acute Chest Infections

Important Safety Considerations

The American Thoracic Society recommends obtaining an ECG to assess QTc interval before initiating azithromycin therapy, and not using azithromycin if QTc >450 ms (men) or >470 ms (women) due to risk of serious cardiac arrhythmias, as supported by evidence from Thorax 1, 2
The use of azithromycin should be avoided with concurrent use of aluminum- or magnesium-containing antacids, which reduces absorption by 24%, according to guidelines from the European Respiratory Society 2, 3

For patients with bronchiectasis and ≥3 exacerbations/year, the British Thoracic Society recommends using azithromycin 500 mg three times weekly OR 250 mg daily for a minimum of 6 months, as supported by evidence from Thorax 4, 5
For patients with COPD, the Global Initiative for Chronic Obstructive Lung Disease recommends using azithromycin 250 mg three times weekly for exacerbation prevention, as supported by evidence from Thorax 1